Audio Database

The

DENON PMA-500
75,000yen(around the 1973 time)

Description
 
The Integrated Amplifier which DENON supplied the track record and technology of the apparatus for pros etc., investigated musicality, and was developed.

The Darlington power transistor of U.S. Motorola, Inc., Inc. is adopted as a power amplifier part in the PNP-NPN pair, and it is circuit composition,It is the PNP-NPN Darlington power transistor symmetry excelled [ power transistor ] in the electrical property, and a whole page direct connection OCL circuit, and low distorted-ization is realized.
Moreover, by taking into consideration the stability of adoption of the Darlington transistor which are 55-200 degrees C and the collector loss 150W, and the temperature compensating of the heat dissipation effect and a bias circuit, Tj fully examines a safe operation domain (ASO), and is designed, and stable operation is realized.

The unguided Hy Rippl type chemical capacitor and the power transformer which made internal resistance small, pressed down the rise in heat, and also took the influence of the leakage flux into consideration from the quality-of-the-material side were made the power-source part, and it takes it.

A preamplifier part is constituted from a direct connection circuit of a high proof-pressure low noise transistor, and has structure in consideration of many characteristics.
Moreover, a power-source part has adopted the buffer amplifier of an emitter follower while measuring stabilization of operation as a regulated power supply.

Two mike input terminals are carried and the full-scale balance type two-channel microphone mixing circuit of microphone amplifier for exclusive use and level regulation volume attachment is carried, respectively.

The muting switch of a three-stage change type is carried.

The standard octal socket and MM/MC changeover switch for MC matching switch are carried.
The socket part has structure which moves MC transformer to a cross direction or a hand of cut, and has all compatibility if it is a thing common octal pin type so that it may not be influenced by a guidance ham.

Functions, such as a low filter, a high filter, a tone-defeat switch, and a loudness, are carried.

Rear
Output
Motorola,
Internal

Rating of a mode
Form All silicon transistor stereo Integrated Amplifier
<Power amplifier part>
Music output 100W
Output power
At the time of a single-sided channel drive : 42Wx2 (8 ohms, THD 0.1%)
At the time of both channel drive : 40W+40W (8 ohms, THD 0.5%)
37W+37W (8 ohms, THD 0.1%)
THD 0.03% or less (at the time of a -3dB Output power)
Cross modulation distortion (60Hz:7kHz=4:1) 0.06% or less (at the time of a -3dB Output power)
Output bandwidth 5Hz-35kHz+0 -1dB (THD 0.1%)
Less than 5Hz-75kHz+0 -3 dB (THD 0.5%)
Frequency response (output Po=10Wconst.) 10Hz-100kHz+0 -1 dB
Input impedance 80kohm±20% (5Hz or less - 20kHz or more)
Input sensitivity 1Vrms/100kohm
Remains noise 0.01 microwatt or less (input terminal short circuit)
S/N ratio 95dB or more
Dumping factor 50 (5Hz or less - 10kHz) or more
Output load impedance 0.16ohm or less (it is pure resistance below 1kHz)
<Preamplifier part>
Output power 1.0Vrms
Maximum except take-off 5.0Vrms
THD At the time of the maximum except take-off: 0.1% or less (100Hz, 1kHz, 10kHz)
At the time of an Output power: 0.05% or less (100Hz, 1kHz, 10kHz)
Cross modulation distortion 0.1% or less (at the time of an Output power)
Frequency response (Tone defeat) 10Hz-40kHz+0 -1 dB
Input sensitivity/impedance Phono1, 2:2mVrms / 60kohm±20%
Media-Interface-Connector: 1mVrms / 100kohm±20%
Tuner, AUX1, 2:100mVrms / 60kohm±20%
Tape PB: 500mVrms / 100kohm±20%
Maximum permissible input (less than THD 1%) Phono1, 2:200mVrms (1kHz)
MIC L/R:80mVrms
RIAA deflection 30Hz-15kHz±0.5dB
S/N ratio (input terminal short circuit) Phono1, 2:65dB or more
Media Interface Connector: 55dB or more
Tuner, AUX1, 2, Tape: 75dB or more
Audio muting 0 -10dB-20dB
Tone control Bass: +10dB--10.5dB (80Hz)
Treble: +10dB--9dB (12kHz)
High Filter 9kHz, 12 dB/oct
Low Filter 40Hz, 12 dB/oct
An Output voltage/impedance Tape rec(DIN): Below 100mVrms/1kohm (40mVrms/80kohm)
<Synthesis>
The semiconductor used Transistor: 39 pieces
FET: Two pieces
Diode: Ten pieces
Varistor: Two pieces
AC outlet switched: Two lines, 250W
unswitched: One line, 150W
Power supply voltage AC100V/120V/200V/220V/240V, 50Hz/60Hz
Power consumption
(Electrical Appliance and Material Control Law)
56W
Dimensions Width 430x height 140x depth of 350mm
Weight 12.5kg